The sender in the expansion tank.

I've had this happen due to corrosion at the contacts where the wires
connect to the sender, too.  Clean that connection well first.

Mike

Keith Pike wrote:
> Just  fired   up the  bomb and  the  water temp light  stays on  blinking;
> heaters  work and  o/f tank is  up. what to check next?
> TIA
> Keith, NL
> Canada
>
>
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